Discussion on Ultra-low Temperature Coolant
There are many kinds of coolant, which are mainly classified according to physical components, but rarely classified according to temperature.Usually, temperature is only an important parameter in model selection. The minimum freezing point temperature of commonly used coolant is generally -40 ℃, and the lower temperature can be defined as ultra-low temperature.And this temperature range is quite broad -40~-145 ℃.-40~-60℃In application, it can be divided into several lower levels. The optional models in the temperature range of -40~-60 ℃ are mainly LM-8 and LM-11.
LM-8 has no flash point and is non-toxic, which is more suitable for immersion freezing or some low-temperature material treatment, while LM-11 has a relatively high flash point, which is suitable for some thermostatic water tanks or industrial applications. This temperature range is applicable to more.-60~-100 ℃, which is a relatively low temperature range, is suitable for scientific research and laboratories.
LM-1/LM-6/LM-14 have different models to choose from. LM-1 and LM-6 have flash points. When using, the system needs explosion-proof design. In addition, the coolant itself is toxic, and personnel should avoid contact during operation.
LM-14 is non-toxic and has no flash point, but the price is relatively expensive. It is a good choice for small experimental systems.In the temperature range of -100~-145 ℃, it is less applicable.
Generally, liquid nitrogen or liquefied gas gasification is used in industries to achieve low-temperature control, but some industries need stable temperature control and continuous operation. Coolant is an ideal choice, and the selection range of coolant in this temperature range is relatively small. LM-6 series models can be as low as -145 ℃.Ultra low temperature coolant is still a relatively wide range, and it is necessary to make an overall selection of the physical properties, toxicity and flash point of the coolant according to the applicable place. In some special processes, an overlay system between the coolant is also required, which makes the coolant into multiple cycles and then superimposes.
At present, there is little research on the application of ultra-low temperature coolant. Glacier Coolant will independently build an Engineering Application Laboratory of ultra-low temperature coolant.
Application of coolant in air source heat pump
The function of air source heat pump is: an energy-saving device that can make heat flow from low-level heat source air to high-level heat source.It is a form of heat pump.As the name suggests, heat pumps, like pumps, can convert low-level heat energy that cannot be directly used (such as heat contained in air, soil and water) into high-level heat energy that can be used, so as to achieve the purpose of saving some high-level energy (such as coal, gas, oil, electricity, etc.).As the demand for cold sources is becoming more and more diversified, the functions of refrigeration and heating are often integrated in a set of equipment.It is common in cold winter and hot summer areas, but in some buildings without heating conditions in the north, air source heat pump products for coolant appear.
In winter, when the outdoor weather may be lower than -20 ℃, in order to maintain the stability of the system, a heat storage box is required. When the outdoor temperature is high, heat storage is carried out in advance. At night or when office work is required, the heat pump is supplemented to release heat energy due to the reduced heating efficiency.Fan coil units are generally used at the end, which are heated in winter and cooled in summer.The coolant in the system needs a high-low temperature switch. The high temperature can reach 60 ℃, and the local minimum temperature in winter may reach -35 ℃ when the low temperature is not used. In addition, there are many materials in the system, such as copper, iron, aluminum, PPR and so on. Therefore, the low-temperature heat pump system has high requirements for the coolant.Conventional automobile antifreeze is prone to corrosion in the process of use, and the system efficiency is seriously reduced.The coolant developed by the glacial coolant pharmaceutical chemical industry has stable performance, and the operating condition is -35~120 ℃, which is practical for low-temperature air source heat pump.
In the operation of heat pump system, the secondary pump system is generally used.It is appropriate to use the water tank of the coolant pump as a closed water tank.If it is an open water tank, under the operating condition of the heat pump in winter, the coolant evaporates quickly, and it is easy to cause the drift of the physical parameters of the coolant when the coolant is supplemented in the later stage. In summer, the low-temperature operation is easy to cause moisture absorption and the freezing point moves up. Therefore, the low-temperature coolant heat pump system needs to regularly detect the physical properties of the coolant and take protective measures. glacial coolant is provided with lifetime free testing.